1. Field of the Invention
The present invention relates to an antenna structure provided in a communication system, and more particularly to an apparatus for enabling an antenna structure to effectively work for various data services in a data communication system and a method therefore.
2. Description of the Related Art
Generally the performance and capacity of a communication system are adversely affected by radio channel characteristics such as same channel signal interference, path loss, multiple path fading, signal delay, Doppler diffusion, and shading phenomenon occurring in a cell and between cells. In order to mitigate these drawbacks, various technologies like power control, channel coding, rake reception, diversity antenna, cell sectoring, frequency division, and/or band diffusion are typically used by communication systems.
However, conventional technologies have difficulty satisfying increasing data communication needs of users and providing high performance and high capacity data communication services. The high performance data communication systems typically include communication systems which can transmit a large amount of data packets such as a moving picture. Accordingly communication systems have been developed to support multimedia communications requiring high quality and high capacity.
Generally the communications systems include a base station and at least a subscriber terminal to provide communication services. The base station exchanges high frequency signals with the subscriber's terminal through one or more antennas. The antennas used for the subscriber's terminals may include directional, omni-directional, monopole, or dipole-type antennas.
The monopole-type antenna is typically used in the subscriber terminal cannot have a gain for a signal portion of horizontal polarization even though the received signal includes both signal portions of horizontal and vertical polarization. On the contrary, the antenna system utilizing both horizontal and vertical polarization such as helical antenna has a high gain because of good signal receptivity.
Although the next generation communication systems are being designed to provide subscriber terminals with various data services, the position of the antenna in the subscriber terminal and other adjacent devices may adversely affect the signal reception. For example, if the user uses game services on the subscriber terminal (which typically require the user to hold the terminal using one or both hands, the user's hand may obstruct the incoming radio waves depending on the position of the antenna in the terminal relative to the user's hand or hands, thereby weakening the signal strength. Hence, the position or direction of the antenna in the subscriber's terminal must be considered in order to effectively receive various data services without weakening the signal strength. To this end, efforts have been made to adapt multiple antennas in the subscriber terminals to effectively receive various high-quality data communication services.